Firmware Engineer

About the role

ButterflyMX is looking for a Firmware Engineer to design, build, debug, secure, and optimise embedded software for next‑generation access‑control and IoT hardware. The role sits at the intersection of electronics, embedded systems, product reliability, and cloud‑connected security.

Key responsibilities

• Develop production‑ready firmware for bare‑metal, Zephyr RTOS, and embedded Linux platforms.
• Write low‑level C/C++ code for microcontrollers, peripherals, sensors and communication interfaces.
• Own firmware from board bring‑up through EVT/DVT/PVT, production release and post‑launch support.
• Collaborate with hardware, mechanical and security teams to resolve multi‑domain failures using lab equipment.
• Implement secure boot, OTA updates, cryptographic authentication and device‑to‑cloud communication.
• Design and debug embedded protocols such as I2C, SPI, UART, BLE, Wi‑Fi and Ethernet.

Required profile

• 5+ years of hands‑on embedded firmware development (8+ years preferred).
• Strong expertise in C/C++ for resource‑constrained systems.
• Experience with bare‑metal microcontrollers, RTOS (Zephyr preferred) and embedded Linux.
• Deep understanding of microcontroller architecture, interrupts, DMA, low‑power modes and bootloaders.
• Practical knowledge of analog/digital electronics, power regulation, signal integrity and debugging with oscilloscopes and logic analyzers.

Required skills

• C and C++ programming.
• Zephyr RTOS and embedded Linux.
• Hardware interfaces: I2C, SPI, UART, GPIO, ADC, PWM, RS‑485, USB, Ethernet, BLE, Wi‑Fi, cellular.
• Secure boot, OTA firmware updates, cryptographic authentication.
• Version control (Git), CI/CD pipelines, static analysis and automated testing.